1. Field
The following description relates to a driving wheel assembly which drives a robot cleaner, and a robot cleaner having the same.
2. Description of the Related Art
In general, a robot cleaner is an apparatus which intakes foreign substances, such as dust, from a floor surface to clean a region to be cleaned while autonomously travelling about the region to be cleaned without manipulation by a user.
Such a robot cleaner includes driving wheels to drive a robot cleaner main body, and the driving wheels drive the robot cleaner main body using frictional force generated between the driving wheels and the floor surface contacting the driving wheels.
In order for the robot cleaner to have consistent traveling performance in various floor conditions, such as a hard floor, or a carpet, for example, frictional force generated between the driving wheels and the floor surface contacting the driving wheels needs to be consistently maintained regardless of the state or condition of the floor surface. For this purpose, applying pressure to the driving wheels in a direction towards the floor surface is required.
Conventionally, a tension coil spring is used to apply pressure to the driving wheel in the direction towards the floor surface. However, the tension coil spring may cause a wide range of applied pressure to the driving wheel according to a displacement of the driving wheel. Furthermore, in order to reduce such range of applied pressure, the length of the tension coil spring is increased. Consequently, an installation space for installing the tension coil spring is increased.